Numerous advances have been made with respect to material handling during manufacture, shipment, transport, and receiving of virtually all types of articles and material. However, one problem that has not been fully addressed is determining when a container, such as a bag, has been filled to a desired level. A need exists for such a system in numerous situations in which it is necessary to supply a signal that indicates when an operator or other equipment should begin filling the next container. The traditional approach to the foregoing problem has been simply to have a human operator monitor the filling or loading process, and when the container is full, activate a switch or perform some other action that causes the filling of another container.
Relying upon a human operator presents several disadvantages and drawbacks. First, human operators are expensive in terms of labor costs. Second, human operators sometimes become bored and inattentive with repetitive tasks, and hence may not provide the desired reliability. Third, human operators may not be able to "reliably" detect when a container is filled within a narrow tolerance level.
Some attempts have been made to construct sensing arrangements that eliminate the need for intense human observation. However, these devices have been directed to very specialized situations. Moreover, prior known devices are relatively expensive and often are not as reliable as desired.
In contrast, the present invention provides a solution to the foregoing problem in that it provides a sensing device that indicates when a container or enclosure is filled to a predetermined level, can be interfaced with automatic filling equipment, or signal to a human operator that the enclosure is full, and is simple, reliable, and inexpensive.